Brain Function Impacted by Smog, Air Pollution, Research Suggests

New studies suggest smog and air pollution can impact brain function, reducing memory capabilities and increasing the risk of stroke.

NPR’s “Talk of the Nation” discussed the results of this study which appears in the most recent edition of Archives of Internal Medicine. The show spoke to Dr. Jennifer Weuve, of Rush Institute for Healthy Aging at Rush University Medical Center, Chicago.

She told NPR the study focused on two “mechanisms” for determining whether air pollution, and specifically, smog affected the brain’s cognitive functions. First, the researchers looked at the effect of exposure to air pollution had on cardiovascular health and the took a closer look to find that visible particulate matter in the air, like smog, can infiltrate the brain.

Weuve said, “And once they’re there, they can cause inflammation, which may be involved in the pathogenesis or progression of dementia. And these particles might even trigger some of those microscopic changes, like the deposition of beta amyloid plaques that are typical of Alzheimer’s disease.”

Researchers found that particulate matter in the air can be ingested or inhaled through various means, including through the mouth or nose and these particles can be transported through the body ending where they ultimately cause the most amount of damage. This includes the likelihood that particulate matter will travel to the brain.

The study focused on the long-term exposure to this particulate matter and how it relates to impaired cognitive functioning. “The most important finding of our study is that women who were exposed to higher levels of particulate matter in the air over the long term experienced more decline in their cognitive functioning over the four years that we evaluated them,” the researcher told “Talk of the Nation”.

Weuve said her team was surprised to find that exposure to visible or “coarse” particulate matter in the air had such an impact on cognitive function. These and the non-visible particulate matter generally considered to be air pollution derive mostly from the burning of things like coal, wood and other carbon-based fuels.

Particulate dust from industrial processes “such as crushing or grinding operations” can also be the source of long-term exposure to these toxins.

The study was not designed to study the short-term effects of particulate exposure and air pollution and how it related to impaired cognitive functions. A partner study however, looked at the impact of high pollution days and believes it could increase the risk of ischemic stroke.

Weuve said reducing air pollution levels, either through practice or policy, will lower the amount of this particulate matter in the air and based on the findings of these studies, could have a major impact on the overall health of aging populations in the U.S. and around the world, where cases of dementia and Alzheimer’s disease are on the rise. Reducing air pollution overall could help “delay the onset” of these mental conditions for as many as 2 million people in the U.S. over the next 40 years.